hi speedfirst,
i dont know whether u can append or not. but you can redirect
the page u want to send if u get such errors
for example
error_page 403 /response.html;
instead of getting 403 in the client response.html will be sent to
client . if U want to send alternate Response to client instead of
sending 403.
Posted at Nginx Forum: http://forum.nginx.org/read.php?2,208911,208918#msg-208918